In the past, it has been known to provide a bus arrangement for interconnecting different components of a transaction system. For example, a vending machine may include a control circuit for controlling the dispensing of products, and a separate coin mechanism for receiving and validating inserted coins. The circuits would be interconnected by the bus so as to permit exchange of data from the coin mechanism to the control board, in order for the control board to be able to determine when sufficient coins have been received for the purchase of an article, so that the article can then be dispensed in response to the appropriate operation of one or more push-buttons of the machine. In some systems, the vending machine control circuit would initiate the information exchange by requesting the appropriate information from the coin mechanism. In other known arrangements, the coin mechanism would initiate the data transfer, and thus trigger the appropriate response from the vending machine control circuit.
Some prior art bus arrangements have been accepted as standard, and have thus provided considerable advantages in permitting independent manufacturers to produce items of equipment which can be readily connected to products of other manufacturers. However, the known bus arrangements also have a number of disadvantages. It would therefore be desirable to provide an improved bus arrangement which is more versatile and faster than known arrangements.